• Many people work as fishermen and in the processing factories in the coastal towns.
  • since it is a desert coast, other types of work scarce. 
 • Fish remains arc crushed and bird droppings (guano) arc collected for fertilizer.

For reasons not fully understood, the south-east trade winds are weaker in some years. Warm water from Indonesia is allowed to drift eastwards across the Pacific. The usual pattern of flow of surface currents is reversed. This happens around Christmas off Peru, which is why Peruvian fishermen gave it the name 'El Nino', meaning the Christ child. This happens every 3-8 years. 

The sudden change in seawater temperature has a dramatic effect on life both in the sea and on the land. Warm ocean water kills plankton and fish, because its currents are low in oxygen and nutrients. Beaches become littered with washed up dead fish and sea birds. The large fish shoals move further offshore into colder waters, out of range of fishermen with only small boats. 

Fish are a major source of food, and in addition, an important source of protein, particularly in developing countries, where diets are often plant-based. Many jobs, both full-time and part-time, depend upon fishing. Apart from fishing itself, there is also work in related processing industries, such as canning, curing and farming for human use. Many of the smaller fish and other organisms, like krill, are processed in factories to make per food, animal feed, and fertilizers. In addition there are related industries, notably boat building, making nets and fishing tackle, and ice production.
  There are wide variations in fish productivity in the world’s oceans. Traditional fishing grounds are located predominantly in the temperate zone of the northern hemisphere due to natural (physical) factors. The main factor is wide expanses of continental shelf--- off the cast coasts of North America and Asia, and off the west coast of Europe. These areas are naturally rich in plankton because of their shallow waters. However, the presence of mineral-transporting ocean currents (Labrador, North Atlantic Drift and Kurile) is also of great significance. Shoal fish such as herring, mackerel, cod and haddock prefer cooler temperate waters. In warmer tropical waters, the nutrient cycle does not function so effectively because a thermo layer occurs because of the lack of mixing between the warm surface waters and the cold deeps.
    Human factors also help to explain the distribution of major fishing grounds. Many 

Coastal regions in temperate areas are heavily populated fish has traditionally formed an important part of the diet, especially in Japan, and in Scandinavian countries like Norway and Denmark. Many boats work in the tropical water, between and around the islands of Indonesia; great quantities of fish arc eaten in many South-cast Asian countries as well, although a lot of the fish eaten in this part of the world comes from fresh-water sources and from fish farming.

Consequences of Overfishing 

Fish stocks on some fishing grounds are now at such low levels that for many year they will not recover the numbers needed for commercial fishing to begin again. All wild populations have their good times and bad; huge surpluses of fish that build up in years when food supply is plentiful are needed to ensure sufficient breeding stock for the lean years which will certainly come. Humans have regarded such surpluses as a gift of nature just waiting to be extracted and are now paying the price.

Hundreds of thousands of jobs in fishing and related industries were lost in the 1990s. Fishing boats were left rusting in ports, worth less than what owners paid for them. Small port communities, in remote locations where fishing is the only source of employment, have been badly hit. The desperate search for new fish supplies is spreading the problem of overfishing to other parts of the world, hitherto untouched,such as the Southern Ocean.

 

Quotas can be supported by other management policies. These include 
 • closed season for fishing, usually during the main breeding time during the year 
 • restricted areas with no fishing allowed so that breeding can take place and stocks recover 
 • limits on net types and sizes so that young fish can swim through the nets, leaving them time to grow to maturity and reproduce. 
 
 

Peru now manages its fishing grounds better than it used to do. Nets are inspected and there is a 2-3 month closed season. Patrols are used to enforce the exclusion zone to keep out foreign vessels, especially Japanese.

 Iceland refused to join the EU (European Union) so that it could keep full control over the management of the rich marine resources within its exclusion zone. Fish account for about 15 per cent-of Iceland's national income and tip .to 70 per cent by value of its exports. The quota to be caught by Icelandic fishermen each year is worked out as shown below.

 • The Marine Research Institute, which is an independent scientific organization, estimates the size of the cod stock aged four years and above. 
 • Fishermen are allowed to catch 25 per cent. 

 

·      Cold-water holds dissolved gases such as carbon dioxide and oxygen better than warm water. 
 Nutrients and minerals are kept in suspension where they can bed try the phytoplankton because of the surface surface currents and regular storms that keep the sea surface rough. 

·      During the long hours of daylight in summer there is almost constant photosynthesis, which allows a high yield of phytoplankton. 

 

 The phytoplankton is the basis of the food chain. The zooplankton in is ocean is dominated by the 5cm this long shrimp-like krill, which feeds on the phytoplankton. Krill often form dense swarms just below the surface, so dense on occasions that the ocean looks Pink. This means that the predators   higher up in the food chain can catch them with the minimum of effort. Krill are the major link in the Southern Ocean and Antarctic food chain, both as a direct and an indirect food supply.